This invention relates to apparatus which is mounted in a hole in a panel from a front side thereof and more specifically to such apparatus which may be clamped tightly to the panel to enable the juncture between device and panel to be sealed against the ingress of dust, fluids or the like.
Apparatus which is to be attached to a panel in a fluid tight or dust tight sealed manner by mounting means which are operable from the front of the panel usually require some form of clamping structure as opposed to a snapin mounting structure. To improve the integrity of the seal between the apparatus and the panel, it is preferable that the clamping structure provide a uniform clamping force against the panel. U.S. Pat. No. 3,876,851 discloses a device which provides a clamping force on four sides of the device to evenly distribute the clamping force, but such device requires a separate adapter and is mounted to the panel from the rear of the panel. Other devices are known in which the clamping mechanism is operated from the front side such as that disclosed in U.S. Pat. No. 3,233,299, but this device provides clamping force only at two opposed sides of the device. Another front mounted device is disclosed in U.S. Pat. No. 4,372,509, this device applying lateral clamping pressure against the edges of the panel opening, not a sealing force against the panel. Still another front mounted device is shown in U.S. Pat. No. 3,273,836 which applies localized clamping forces at two diagonally opposed corners of the device and does not distribute the forces uniformly around the device.